There are mainly two types of magnets: One is Samarium Cobalt magnet and another one is Neodymium magnet. The physical properties for these two types of magnets can be found on http://www.magnetsales.com/SMCO/smcoprops.htm and http://www.magnetsales.com/Neo/Neoprops.htm. Here we list some of them that are relevant to our investigations.
Description |
SmCo 1-5 Alloys |
SmCo 2-17 Alloys |
NdFeB |
Young's modulus |
158 GPa |
117 GPa |
166 GPa |
Density |
8.2g/cm3 |
8.4g/cm3 |
7.4g/cm3 |
Remanence (Br) |
0.8T to 1.2T |
0.8T to 1.2T |
0.7T to 1.4T |
Coercivity (Hc) |
~800kA/m |
~800kA/m |
500kA/m to 1000kA/m |
Intrinsic Coercivity (Hci) |
710kA/m to 2000kA/m |
710kA/m to 2000kA/m |
710kA/m to 3000kA/m |
Recoil permeability |
1.05 |
1.05 |
1.05 |
Curie temperature |
750°C |
825°C |
310°C |
Temperature coefficient |
-0.043%/°C |
-0.03%/°C |
-0.09 to 0.13%/°C |
Maximum Operating Temperature |
250°C |
300°C |
150°C |
Electrical Resistivity |
5µ ohm cm |
86µ ohm cm |
160µ ohm cm |
To understand what those quantities represent, we can look at the hysteresis curve for a typical magnet as shown in the figure below.
Here 
is the remanence which is the remained magnetization of the permanent magnet when the external fields are removed; 
is the coercivity (those who forget its meaning can refer to http://en.wikipedia.org/wiki/Coercivity.); 
is the recoil permeability which is the slope for the magnetization and demagnetization as shown in the hysteresis curve; 
is the intrinsic coercivity. The difference between coercivity and intrinsic coercivity can refer to http://www.mceproducts.com/knowledge-base/article/article-dtl.asp?id=86.